Is minimally invasive approach to genioplasty predictable for mentolabial soft tissue? A retrospective cohort study.

[INTRODUCTION] The aim of this study was to conduct a three-dimensional analysis of the effects on mentolabial soft tissues of three different orthognathic surgery protocols: bimaxillary surgery without genioplasty, bimaxillary surgery with conventional or minimally invasive genioplasty (MIS).

[MATERIALS AND METHODS] Pre-operative and post-operative CBCT were superimposed to quantify and ascertain the direction of mandibular movements, and soft tissue were analyzed to evaluate the hard to soft tissue ratio. Data from 97 consecutive patients were evaluated: 30 conventional genioplasty, 36 MIS and 31 no genioplasty.

[RESULTS] The impact of the surgical movements on the overlying soft tissues can be consider with stronger correlation in the group No Genioplasty in the whole mentolabial region, stronger correlation in labial and pogonion region in the MIS group and no stronger correlation in the conventional group.

[CONCLUSIONS] Sutures in the mentolabial region directly interfere with the postoperative impact of orthognathic surgery on soft tissues in mentolabial area, in both the vertical and horizontal directions. A smaller incision - consequently involving less detachment of soft tissues in the region - may promote a lower risk of chin ptosis, in addition to greater suspension of the musculature.